摘要 |
FIELD: electricity; motors and pumps. ^ SUBSTANCE: protection device consists of current transformers, magnetic starter, three-phase AC power supply, rectifier, overload control unit, current-time curve generation unit. The latter unit is comprised of a thermal electrical motor imitator based on operating amplifier with the negative feedback parallel RC coupling, comparator and final control relay. The operating amplifier of the thermal imitator is covered with the positive T-shaped RCR coupling. ^ EFFECT: increased device actuation accuracy and timely tripping of electrical motor. ^ 2 dwg |